Glow discharge relay



1935. H-. C THoMPsw' GLOW DISCHARGE RELAY Filed bee '7, 1931 1 m t n M S n H. I

va H Patented Nov. 12. 1935.

v circuit arrangement 2,021,034 g GLOW nrsonsnon may Barry C. Thompson, East Orange, N. 1., align" or 10 Gtlsrlkfll Electric Company, a corporation of Application December 1, 1031, semi No. 579,01 11 Claims. (01. est-41.5)

My invention relates to means for controlling electric circuits and more particularly, to means employing glow discharge tubes in a relay circuit.

relay 3 may be connected to control a circuit such as indicated by the lamp load I.

In operation, the alternating current voltage The light-sensitive cell 6, parallel to glow discharge device I, normally has a high impedance so that the potential across the 15 discharge devices is substantially equally divided. I! light from a source such as is indicated at 8 is allowed to impinge upon the light-sensitive cell 6, the impedance of the light-sensitive cell is reduced so that the voltage across glow discharge device 2 increases and a corresponding decrease a desired control operation.

Another object of my invention is to provide a trolled which may be. !or, example, a lamp load shown at 1. This control circuit energizes the relay as long as light from a 'source- 8 impinges on the light-sensitive cell 6. When the light no longer-impinges upon the light-sensitive cell 6, the glow through the discharge devices I and 2 conductors in the proximity oi the control circeases because the glow breaks or ceas s dur n 40 cult; and Fig 6 is a still further embodiment of each cycle of the alternating current. In this my invention in which the control circuit is acmanner it will be apparent the control circuit tuated by high frequency currents. may be used to energize or de-energize the cir- Referring to Fig. l of the drawing. I have iiluscuit to be controlled.

trated therein a control circuit including two 11 desired,'the arrangement, in Fig. 1 may be operated from a direct current source. I! the leads I are connected to a direct current line glow discharge devices which Another arrangement of Fig. 1 may be obtained by removing the transformer I and 'connecting the relay coil 3 and the glow discharge devices I and 2 to the leads I. The leads 5 may tial across the glow discharge devices i and 2. Glow discharge device i has a light-sensitive cell 6 connected in'parallel thereto. The contacts 01 and 16 which then be connected to a source of direct current potential of proper polarity insufficient to cause the discharge devices to glow, but suilicient to maintain the glow when started. In such an arrangement the presence of light upon lightsensitive cell 6 causes the glow discharge cells to glow in succession and the relay to he operated. The glow discharge devices continue to glow even when the light no longer impinges upon light cell 6, because the glow potential does not go through a negative cycle as was the case in the alternating current arrangement. To stop the glow of the discharge devices and to release the relay, the direct current must be interrupted by a sv 'tch. In some applications this direct current arrangement may be highly desirable, where it is desired to arrange an alarm which remains actuated until an operator manually releases it. Referring to Fig. 2, I have illustrated therein a pair of glow discharge devices H and 12 con-- nected in series with the secondary winding of transformer 13 and the winding of relay 14. The capacities of the electrodes of glow discharge devices are balanced by means of capacitors l5 are connected in parallel with the respective glow discharge devices. Glow discharge device H has a light-sensitive cell. l1 connected in parallel thereto and glow discharge device 12 has a resistance l8 connected in parallel thereto to balance the photo-electric current which is flowing through the light-sensitive cell i1 when light from source 20 impinges upon the cell. Relay [4 may have a resistance l9 connected in parallel thereto to prevent actuation of the relay by the leakage current of light-sensitive cell H. An alternating current potential insufficient to cause glow is impressed across-glow discharge devices ll, l2 by means of the transformer l3 which is connected to an alternating current line 8. The relay 14 may be used to control any load circuit which is represented by the lamp load l0.

I'he combination of the glow discharge devices H and 12. the capacitors l5 and I6, and the lightsensitive cell l1, and resistor l8 constitutes a balanced bridge circuit which becomes unbalanced when light from source 20 no longer impinges upon the light-sensitive cell l1, thereby causing a greater potential to be impressed across glow discharge device ll. than across glow discharge device I2 This increase in voltage across device 1 l causes it to glow, whereupon the voltage across this device drops so that a greater part of the line voltage appears across glow discharge device 12 which in turn also glows, thereby allowing current to how through both of the glow discharge devices. This current is suificient to operate relay i4, thereby energizing the circuit to be controlled which may be, for example, a lamp circuit shown Hi. The relay 14 of the control circuit is energized as long as light from a source such as 28 does not impinge upon t-sensitive cell ll. such a circuit may be used to turn on lights when natural daylight falls below a certain intensity. Other applications such as counting systems, alarms, smoke detectors, sorting devices and the like may be controlled by this invention, as the mechanism would operate whenever the light beam from a source, such. as 20, is intercepted by an object.

lhe arrangement described above may be arranged operate on direct current moving the transformer i3 and connectir a glow discharge devices and relay directly to the capacities of the component parts.

9. In the direct current operation the balancing capacities l5 and I6 are not essential as there is no appreciable transfer of energy through In the direct current arrangement the glow in the discharge devices continues until the direct current is interrupted.

In Fig. 3, I have illustrated an embodiment of my invention which will indicate the presence of a passing body. Two glow discharge devices 2! and 22 are connected in series with the secondary winding of transformer 23 and the winding of relay 24. An alternating current potential is impressed across glow discharge devices H and 22 by means of transformer 23 which is connected to an alternating current line 25. Relay 24 may be used to control a circuit such as is indicated at 26. A metallic capacitor plate 21 is connected to one of the electrodes of glow discharge device 22 and a similar-capacitor plate 28 is connected to the other electrode of the device 22. The capacitor plates 21 and 28 are arranged in the same plane, and to balance the effect of the capacity between these plates a capacitor 29 is connected across the device 2|. If a body 30 is moved in a plane parallel to that of capacitor plates 21 and 2B, in the direction shown by the arrow, the capacity across cell 22 will be increased and thus the voltage balance across the glow discharge devices will be changed so that the cells are energized successively to operate the relay 24. This arrangement operates very readily when the body 30 is of a conducting material, and will also operate if body 30 is a non-conductor of suiiicient magnitude and suil'iciently near the plates 21 and 2B.

A modification of Fig. 3 is shown in Fig. 4 which shows those elements which may be rearranged to obtain a more sensitive arrangement when capacitor plates 21 and 28 are to be used to denote the presence of a non-conducting body. In this figure similar parts are given the reference characters corresponding to those shown in Fig. 3. In this instance, however, the body 3| glow discharge may be one of insulating or non-conducting ma- 1 terial passed betw en capacitor plates 21 and 28 which are arranged in planes parallel to each other. The insulating or non-conducting body 3i is moved in the direction shown by the arrow to increase the capacity across glow discharge device 22, thereby disturbing the voltage balance across the glow discharge devices to such an extent as to energizev them successively.

The arrangements shown in Figs. 3 and 4 may be applied to counting relays, sorting devices. safety devices, limit switches, automatic inspection devices and many other arrangements.

Another modification of my invention is illustrated in Fig. 5 in which I have arranged glow discharge devices 32 and 33 in series with relay 34 and the secondary winding of transformer 35, the primary winding of which is connected to the alternating current line 35. Relay 34 controls the "ization apparatus indicated by the rece 31. A. acitor plate 38 is connected to e electrode of d charge device 32 which is connected to the relay 34. A similar capacitor plate 39 is connected to the electrode of device 33 at the point where it is connected to the secondary winding of transformer 35. A third plate 40 similar; to the plates 3E'a.id 39 is connected to point between the disc-harm devices 32 and 33. The capacitor plates are arranged in line in the This arrangement provides equal paciws across ea= L). of the glow discharge dewinding 52 of transformer 53.

vices 32 and 33. A series of capacitor plates of equal size and proportional to the capacitor plates 38, 39 and 40 are arranged in a plane parallel to these plates. The plate 4| is connected to plate 43 and is also connected to one terminal of the winding of transformer 44. The other terminal of this winding of the transformer is connected to the plate 42 which is arranged between capacitor plates 4i and 43. The primary winding of transformer 44 is connected to a source of alternating current shown at 45 and a switch 48 is included in the circuit so that the transformer may be energized at will. If the capacitor plates 4|, 42 and 43 are arranged in a plane parallel to and opposite the plates 38, 39 and 40, an actuation of the switch 46 will impress upon these capacitor plates an alternating potential which will be transferred to the capacitor plates connected to the electrodes of the glow discharge devices. the division of voltage across the glow discharge devices 32 and 33 and it is apparent that this will cause the glow discharge devices to be enersized in succession in a manner similar to that in the preceding figures. If the switch 48 is closed and the conductors or capacitor plates 4i, 4i. 43 are moved in the direction shown by the arrow, the voltages across glow discharge devices 32 and 33 will become unbalanced. In this arrangement the distance between the two sets of capacitor plates may be greater, or the sizes of these plates may be considerably smaller than in the arrangement shown in Fig. 3 where the capacitor plates are not energized.

An arrangement of this kind may be applied to a communication system between an operator and trains. Such responses as the automatic operation of breaks could be obtained, as well as actuating warning signals in the cab of the train operator.

Referring to Fig. 6 of the drawing, I have illustrated therein, a tuned radio circuit 41 provided with an antenna and ground and having its output connected to an electron discharge device 48. The electron discharge device 48 which may be of the screen-grid type, is provided with a cathode, two control elements and an anode. The output of the radio circuit 41 is connected to one of the control elements and the cathode of the device 48. I have arranged two glow discharge devices 43, 50 in series with the relay and the Transformer 53 is connected to a suitable alternating current source by means of conductors 54. A winding 55 of the transformer provides a. source of current for heating the cathode of device 48. The anode of discharge device 48 is connected to a point between glow discharge devices 49 and 50, and the remaining control element of discharge device 48 is connected to the electrode of glow discharge device 50 which is connected to the winding 52 of transformer 53. The relay 5! may. be arranged to control any desired circuit.

In operation, the radio circuit 41 has high frequency current impressed thereon by means of the antenna, and the output of the radio circuit impresses a voltage upon the control element of discharge device 48 which eiiects a change in impedance of the discharge device. This change in impedance unbalances the distribution of voltage across discharge devices 49 and 50 which causes them to be energized in succession, thereby allowing current to flow through the relay 5|.

My invention therefore has the advantages: (1) that the controlling or relay circuit does not This transfer of energy will unbalanceconsume energy unless a controlling operation is being performed; and (2) that an arrangement or simple apparatus inexpensive to construct and maintain provides a sensitive control apparatus.

While I have shown and described my invention 5 in connection with certain specific embodiments it will, of course, be understood that I :20 not wish to be limited thereto, since it is apparent that the principles herein disclosed are susceptible of numerous other applications, and modifications which may be made in the circuit arrangemnts or in the instrumentalities employed without departing from the spirit and scope of my invention as set forth in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a relay control circuit, a pair of glow discharge devices connected in series, a variable impedance connected in shunt to one of said devices, connections to said devices for supplying thereto a pulsating potential having a peak value substantially less than twice the, break-down voltage of one glow discharge device and greater than twice the minimum glow voltage of one device whereby in response to a variation of said impedance said glow discharge devices break down and pass current, means responsive to current in said discharge devices, and means to vary said impedance during a normal condition of voltage across said glow discharge device sumciently to cause said glow discharge device to break down and operate said current responsive means.

2. In a relay control circuit, a pair of glow discharge devices connected in series, a pulsating potential connected across said devices having a peak value substantially less than twice the breakdown voltage of a single glow discharge device, means for decreasing the potential across one of said glow discharge devices while the sum of the voltages across the two glow discharge devices is normal whereby the potential across the other of said devices become suflicient to cause breakdown thereof, and means responsive to breakdown of said discharge devices.

3. In a control circuit, a pair of glow discharge devices, a source of alternating potential connected to said devices so that the peak potential impressed upon each device is substantially less than the breakdown glow potential and greater than the minimum glow potential of said device, and light-sensitive means connected in said control' circuit for successively increasing the potential across said devices whereby said devices are energized successively, and means responsive to the energization of said devices. 55

4. In a control circuit, a current responsive device and a pair of glow discharge devices connected in series, a source of alternating potential connected to said devices, said alternating potential having a value less than twice the breakdown glow potential and greater than twice the minimum glow potential of a single one of said devices, an impedance connected in parallel with one of said devices and a variable impedance connected in parallel with the other of said devices, means for changing said variable impedance during normal voltage conditions across said glow discharge devices whereby said glow discharge devices are energized in succession to pass current through said circuit.

5. In an electric circuit, the combination of a pair of glow discharge devices connected in series,

a relay connected in series with said devices, a source of alternating potential connected to said relay and said devices, said source of alternating said devices'to become conductive,a group 0! capacity plates arranged adjacent to each other, one of said capacity plates being connected to a point between said glow discharge devices and the remaining capacity plates being connected to either side of said devices, a second group oi plates arranged opposite said first group of plates, and means for applying a potential to said second group 01 plates whereby said glow discharge devices become conductive in succession to pass current.

6..In an electrical circuit, a pair of glow discharge devices connected in series, a control means connected thereto, a source-oi alternating potential connected to said devices and said control means of a value substantially less than twice the breakdown glow potential and greater than twice the glow potential or a single device, and light-sensitive means connected across one 0! said discharge devices for energizing said giowdischarge devices in succession.

'7. In combination, an electric circuit, means for closing said circuit, said meansincluding a control circuit containing a relay and a pair of glow discharge devices connected in series, a source of alternating potential connected to said control circuit, the value c! the potential being lower than that required to break down said glow discharge devices and produce a flow of current in said control circuit, means connected to said circuit res" nsive to the presence of an object for automatically increasing the potential across one of said discharge voltages across said glow discharge devices is normal thereby to produce a flow 0! current therethrough and to impress on said second glow discharge device a potential suflicient to produce a flow 01 current therethrough, whereby a current will be caused to flow through the control circuit to energize said relay.

8. In combination, an electric circuit, means for closing said circuit, said means including a control circuit containing a relay and a pair of glow discharge devices connected in series, a source of alternating potential connected to said control circuit, the value oi the potential being somewhat lower than twice that required to break down a single glow discharge device to produce a flow of current therethrough and greater than twice the minimum potential necessary to maintain a glow in a single discharge device, means connected to said circuit responsive, during normal voltage conditions across said glow discharge devices, to high frequency current, said means automatically shifting the distribution of potential across said glow discharge devices whereby the potential impressed on one of said glow disdevices while the sum of thepotential having a. peak value insumcient to cause a charge devices becomes sunicient to produce a how of current therethrough, and the operation of said glow discharge device thereby increasing the potential across the other oi said glow discharge devices to produce a now oi'current there- I through, whereby a current will flow through said control circuit to energize said relay.

9. In combination, an electric circuit, means for controlling the closing of said circuit, said means including a control circuit containing a relay 1i) and a pair of glow discharge devices connected in series, a source of alternating potential connected to said control circuit, the value of said potential being less than that required to break down said glow discharge devices and produce a 15 flow of current therethrough, and means connected to said circuit, including an electron discharge device responsive, during a normal condition oi voltage across said glow discharge de vices. to high frequency current, said means in 20 response to high frequency current automatically shiitingthe distribution oi potential across said glow discharge devices to energize said devices in succession, whereby a current how will be produced to energize said relay.

10. The method of controlling a circuit provided with a pair of glow discharge devices connected in series, which includes impressing on said glow discharge devices an alternating potential of a value substantially less than twice 30 the breakdown glow potential and greater than twice the minimum glow potential of a single one oisaid devices, and successively energizing said glow discharge devices by increasing the potentialacross one oi said devices while the sum of the 85 voltages across said two glow discharge devices is normal, decreasing the potential across the other 01 said devices, and causing a flow of current in the circuit.

11. Means for operating an electric device com- 40 prising, a plurality of gaseous discharge tubes connected in series with said device and across a source of E. M. F. 0! a value less than the sum of the E. M. F.s necessary to initiate a discharge in the individual tubes as long as the E. M. F. is distributed equally over the tubes, a photoelectric cell, and means associated with the photoelectric cell and the discharge tubes for altering the distribution of E. M. F. over the discharge tubes upon a change in light intensity at the photoelectric cell, whereby one discharge tube becomes a relatively good conductor and increases the potential across another discharge tube to a value whereat it also becomes a good conductor so that a comparatively large current flows through said discharge tubes and the electric device.

HARRY C. THOMPSON. 

